1. Field of the Invention
A method and apparatus is disclosed for uniformly finishing the working surfaces of rotating automotive parts.
2. Background of the Prior Art
Automotive vehicles require a substantial number of rotating parts which have working surfaces which are in intermittent sliding contact with other parts, usually having pads made partially or solely from non-metallic heat resistant materials. Examples of these are clutch disks and clutch plates encased in a clutch drum housing of an automatic transmission. The clutch pack is a stack of alternating steel clutch plates and steel clutch disks having a fiber layer on both sides. The clutch plates usually have splines on the outside which fit splines on the inside of the housing while the clutch disks usually have splines around an opening on the inside which are engaged by a shaft running through the housing. The clutch pack is designed to lock up whereby the shaft and housing rotate together. The housing is generally cylindrically shaped with a working surface around the outside that is engaged by one or more belts. Other examples of parts that can be repaired include the working face of a fly wheel which is engaged by a conventional mechanical clutch and brake rotors which have working surfaces on both sides which are engaged by disk brake rotor pads.
Repeated engagement and disengagement of the fibrous material of the clutch disks or brake pads together with the combined effects of heat and chemical reactions, such as oxidation or hydration, results in glazing of the working surfaces over time. The glazed surfaces are nonuniformly glazed. Glazing of these surfaces can result in undesirable slippage or inconsistency. In the case of automatic transmission clutch packs, smoothness of operation can be undesirable affected. Therefore, there is a need in the automotive repair art to deglaze working surfaces of rotating parts. The deglazed surfaces need to be uniformly deglazed and refinished.
Equipment is available to deglaze working surfaces of rotating automotive parts, but it is expensive and difficult to operate and maintain. Many of the automotive repairs that are done in the United States are done in small shops dispersed throughout the country. There has been a need for an economic alternative to hand sanding which is time consuming and difficult to perform in such a way to produce a uniform surface on both sides of a circular plate. Because the job is especially onerous when rebuilding automatic transmissions which have multiple plates, workmen are prone to simply replace the old parts without adequate sanding or alternatively, throw them all away and replace them unnecessarily with costly new parts.